The proposed research involves both psychophysical measurements and black-box modeling. The research is focused on binaural interference, conditions in which performance with two ears is worse than performance with one ear. The understanding of these conditions not only has theoretical ramifications, but more important is the possibility for improvements in the quality of life of the hearing-impaired. Psychophysical results, in which monotic is better than dichotic, are not explained by current auditory models. Specifically, monaural intensity discrimination will be measured under monotic and dichotic conditions; the dichotic conditions are chosen to give the largest decrease in performance relative to the monotic condition. This dichotic/monotic psychophysical work is inherently linked to the interactions of interaural differences (specifically differences in time, level, and coherence) on perception. The results from these psychophysical studies will aid in the design of an auditory model which can explain much of the classical auditory perception data and also explains conditions in which two is worse than one.